8,206 research outputs found
Probing the ZZgamma and Zgammagamma Couplings Through the Process e+e- --> nu anti-nu gamma
We study the sensitivity for testing the anomalous triple gauge couplings
and via the process
at high energy linear colliders. For integrated luminosities of 500
and center of mass energies between 0.5 and 1.5 , we find that this
process can provide tests of the triple neutral gauge boson couplings of order
, one order of magnitude lower than the standard model prediction.Comment: 12 pages, 6 figure
The Stationary Phase Method for a Wave Packet in a Semiconductor Layered System. The applicability of the method
Using the formal analysis made by Bohm in his book, {\em "Quantum theory"},
Dover Publications Inc. New York (1979), to calculate approximately the phase
time for a transmitted and the reflected wave packets through a potential
barrier, we calculate the phase time for a semiconductor system formed by
different mesoscopic layers. The transmitted and the reflected wave packets are
analyzed and the applicability of this procedure, based on the stationary phase
of a wave packet, is considered in different conditions. For the applicability
of the stationary phase method an expression is obtained in the case of the
transmitted wave depending only on the derivatives of the phase, up to third
order. This condition indicates whether the parameters of the system allow to
define the wave packet by its leading term. The case of a multiple barrier
systems is shown as an illustration of the results. This formalism includes the
use of the Transfer Matrix to describe the central stratum, whether it is
formed by one layer (the single barrier case), or two barriers and an inner
well (the DBRT system), but one can assume that this stratum can be comprise of
any number or any kind of semiconductor layers.Comment: 15 pages, 4 figures although figure 4 has 5 graph
Deep into the Water Fountains: The case of IRAS 18043-2116
(Abridged) The formation of large-scale (hundreds to few thousands of AU)
bipolar structures in the circumstellar envelopes (CSEs) of post-Asymptotic
Giant Branch (post-AGB) stars is poorly understood. The shape of these
structures, traced by emission from fast molecular outflows, suggests that the
dynamics at the innermost regions of these CSEs does not depend only on the
energy of the radiation field of the central star. Deep into the Water
Fountains is an observational project based on the results of programs carried
out with three telescope facilities: The Karl G. Jansky Very Large Array
(JVLA), The Australia Telescope Compact Array (ATCA), and the Very Large
Telescope (SINFONI-VLT). Here we report the results of the observations towards
the WF nebula IRAS 180432116: Detection of radio continuum emission in the
frequency range 1.5GHz - 8.0GHz; HO maser spectral features and radio
continuum emission detected at 22GHz, and H ro-vibrational emission lines
detected at the near infrared. The high-velocity HO maser spectral
features, and the shock-excited H emission detected could be produced in
molecular layers which are swept up as a consequence of the propagation of a
jet-driven wind. Using the derived H column density, we estimated a
molecular mass-loss rate of the order of Myr. On the
other hand, if the radio continuum flux detected is generated as a consequence
of the propagation of a thermal radio jet, the mass-loss rate associated to the
outflowing ionized material is of the order of 10Myr.
The presence of a rotating disk could be a plausible explanation for the
mass-loss rates estimated.Comment: 10 pages, 5 figures. Accepted for publication in A&
Horizontal target strength-size conversion equations for sea bass and gilt-head bream
[EN] Horizontal hydroacoustics is a technique of remote fish detection that has proved to efficiently determine fish density and biomass in shallow or superficial waters. This non-intrusive technique could render better results than those obtained by conventional sampling when monitoring shallow waters. To apply this technique, we need equations that relate the amount of sound returned by fish, known as target strength (TS in dB), with their length (mm) or weight (g). This study presents horizontal conversion equations for the species gilt-head bream (Sparus aurata) and sea bass (Dicentrarchus labrax), two of the most important species bred in aquaculture. Moreover, this study presents a new formula to calculate a mixed equation adjusted to the percentage of distribution of those species in case of mixed populations. The results in this research have been obtained by applying a simple setup that allows for high-quality acoustic data. These new equations will enable the application of this technique in order to estimate these species' density and biomass in shallow aquatic systems such as aquaculture ponds with semi-intensive production densities.This study's authors would like to thank the Superintendent of Economy and Knowledge (Andalusian Government) for the funding provided as part of the project (PI_57052) developed in collaboration with CTAQUA. We would like to thank the researchers Carlos Orduna Marin and Juan Ramon Cid Quintero for their selfless work to obtain the field data and to the company PIMSA for generously allowing us to use their facilities and fish. We would also like to thank the veterinarian JR Rodriguez for being kind enough to perform X-rays on the studied fish and Cristina Ocana for her careful proofreading of the English text.RodrĂguez-SĂĄnchez, V.; RodrĂguez-Ruiz, A.; PĂ©rez Arjona, I.; Encina-Encina, L. (2018). Horizontal target strength-size conversion equations for sea bass and gilt-head bream. Aquaculture. 490:178-184. https://doi.org/10.1016/j.aquaculture.2018.02.034S17818449
Long-Term Influence of the Practice of Physical Activity on the Self-Perceived Quality of Life of Women with Breast Cancer: A Randomized Controlled Trial
[EN] Background: There is still no consensus on the most suitable interventions for exercise practice in breast cancer survivors. Therefore, the aim of this study was to evaluate the effect of a two-year physical activity intervention (strength, aqua fitness and aerobic exercise programs) on the self-perceived quality of life and physical functionality of female breast cancer survivors. Methods: A randomized, controlled, experimental trial with a sample of 316 women (63 ± 7 years), who had been diagnosed with breast cancer. The evaluations were performed using the Rikli & Jones Senior Fitness Test, and the Short Form 12 Health Survey (SF-12). Results: The participants in the strength program showed statistically significant improvements in all the items of the SF-12. The aqua fitness program obtained significant improvements in Physical Functioning and Limitations, Pain and Emotional Limitations, General Health, Vitality, Social Functioning and the physical and mental components of the SF-12. The participants in the aerobic program showed a progressive deterioration of Vitality and Mental Health. Conclusion: When assigning breast cancer survivors to an exercise program, the preferential or predominant activity should include strength exercises. On the other hand, as the second choice, those patients with particularly low levels of Vitality or Physical Limitations will show greater improvement with an aqua fitness program.S
Comparisons of the Health Benefits of Strength Training, Aqua-Fitness, and Aerobic Exercise for the Elderly
[EN] Objective. To compare strength training, aqua-fitness, and aerobic exercise programs to discern the differences in the benefits achieved by each of the activities in older people. Design. Double-blind randomized trial. Setting. Controlled clinical environment. Participants. 108 people: 54 female paired with a male of the same age (average age of 65.5 ± 5.6 years). Interventions. Three exercise programs (aqua-fitness, aerobic exercise, and strength training) for six months. Main Outcome Measures. Body Mass Index, Senior Fitness Test (which evaluated functional fitness), and the SF-12 Health Survey. Results. Men showed greater positive changes in the aerobic exercise group for general self-perceived mental health, leg strength, and flexibility of legs and arms. The largest improvements in overall self-perceived physical health and upper limb strength were in the men of the strength training group. The women participants in the strength training group obtained greater benefits, especially in self-perceived mental and physical
health and in the strength of the four limbs. Conclusions. To maximise benefits, older people, in general, may want to consider participating in aerobic activity. Furthermore, older women would benefit greatly, both emotionally and physically, from exercise that includes strength training.S
The influence of sonication on the thermal behavior of muscovite and biotite
The differences on the thermal behavior (DTA-TG) of mica samples measured
before and after sonication have been studied. Sonication treatment produces
important modifications in the thermal behavior of muscovite and biotite
samples. For muscovite, it produces a broadening and decrease in temperature of
the dehydroxylation and crystallization effects, reaching a steady stage after
40 h treatment time. For biotite, the original single peak profile for the
dehydroxylation of the untreated sample is converted into a two peaks profile
after sonication, the intensity of the low temperature peak increases with
sonication time, while the intensity of the high temperature peak decreases.
The modification of the thermal behavior for sonicated samples has been
correlated to the particle size distribution effect produced by the sonication
treatment. It has been also observed that the cup tip of the sonication
equipment contaminates the samples releasing titanium of its compositio
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